Development of a Nonlinear Binary Programming Model for Intersection Improvement Prioritization

A model is presented that utilizes nonlinear binary mathematical programming and the predictive crash methodology found in the AASHTO Highway Safety Manual to prioritize the selection of intersection safety projects. This research improves upon methods employed by prioritization tools such as the Interactive Highway Data Safety Design Model (IHSDM) and AASHTO Safety Analyst by the ability to implement multiple countermeasures at individual intersections. This expansion is advantageous in that it that it allows greater flexibility in determining mitigation strategies. For real life applications, implementation of multiple countermeasures can also decrease overall project expense by reducing construction mobilization and oversight costs. A sample set of intersections is analyzed using the nonlinear binary method and results are compared to a similar model utilizing a single countermeasure or a single set of predetermined countermeasures.